The present invention relates to a method of cooling and effecting a change in state of a liquid mixture, in particular a liquid mixture for food, drugs, fertilizers, detergents, cosmetics, catalysts, enzymes or parasiticides.
Two types of systems are normally used for cooling and effecting a change in state of a liquid mixture.
In a first, the liquid mixture is placed and kept inside a vessel having a cooled inner surface, until the mixture is cooled to other than the liquid state.
In the second, the liquid mixture is fed along a cooling tunnel having a cooled inner surface and long enough to cool and effect a change in state of the liquid mixture.
Since the liquid mixture has a relatively small cooling surface and cools progressively inwards from the outermost layers, the above known systems have several drawbacks, foremost of which is the relatively long time taken to cool and effect a change in state of the liquid mixture.
A further drawback of the above known systems lies in output being proportional to the size of the cooling vessel and tunnel, so that, to achieve a relatively high output, the systems must be fairly large, and are therefore expensive to produce as well as to run in terms of energy consumption.
Apparatuses for the rapid freezing of liquids which partially overcome the aforementioned drawbacks are disclosed in EP-A-0659351 and U.S. Pat. No. 1,970,437.
EP-A-0659351 discloses an apparatus for the rapid freezing of liquids comprising an atomizer defined by at least one nozzle and able to atomize a liquid mixture in a freezing turret. The turret is provided with a plurality of nozzles, which supply to the interior of the turret cooling means able to effect a change in state of the liquid mixture.
U.S. Pat. No. 1,970,437 discloses an apparatus for the rapid freezing of liquids comprising an atomizer defined by a shower bath, a Segner wheel, a pulverizer, or a sprinkler and able to atomize a liquid in a freezing turret. The turret is provided with a plurality of pipes which supply to the interior of the turret cooled air able to effect a change in state of the liquid mixture.
However, due to the fact that in the apparatuses disclosed in EP-A-0659351 and in U.S. Pat. No. 1,970,437 the liquid mixture is atomized under pressure, such apparatuses have to be provided with very long freezing turrets, which are cumbersome and expensive.
It is an object of the present invention to provide a method of cooling and effecting a change in state of a liquid mixture, designed to eliminate the aforementioned drawbacks.
According to the present invention, there is provided a method of cooling and effecting a change in state of a liquid mixture as recited in claim 1.
The present invention also relates to a system for cooling and effecting a change in state of a liquid mixture.
According to the present invention, there is provided a system for cooling and effecting a change in state of a liquid mixture as recited in claim 14.